In a prison in Rome, real-life convicts prepare to mount a production of William Shakespeare’s “Julius Caesar,” and as the night of the public performance draws nearer, their real lives and the play’s narrative conflate to the point of indistinguishability. So runs an approximate logline for the Taviani brothers’ “Caesar Must Die” which arrived at the Karlovy Vary Film Festival trailing glowing reviews and the Golden Bear from Berlin in its wake. And given that summation, it’s easy to see why it won – there are few themes more festival-friendly than the interrelatedness of art and life. But there’s a difference between suggesting that such a relation exists and exploring or commenting on its nature, a difference the veteran directors, and the more breathless of the film’s admirers, seem only sporadically to acknowledge.

Not that there is not a lot to enjoy here. The film is undeniably moving at times, and there are moments of metatextual elegance that feel as though they tremble on the brink of genuine insight. The largely non-professional cast (only the lead, Salvatore Striano who plays Brutus, is now a professional and only since receiving a pardon having served a term in this very prison) and the completely authentic surroundings (the film is shot on locations within the prison walls), lend proceedings a welcome rawness, only a little romanced by the extensive use of black and white photography. And it is never less than absorbing. Moving us onward in the wider story as we move later through the play is a clever touch that means that forward momentum is at all times maintained, and performance night becomes the convergence point for the climaxes of both strands.

But the film’s strength and point of differentiation — using real-life prisoners to play the roles — also proves its chief flaw. There is a lack of focus around quite what the directors are trying to get at; we were told before our screening that their aim was to show that prisoners are human too, which sounds simultaneously like it’s too small an ambition for such an overtly experimental approach, and too large a claim for the resulting film. Because once the film gets going, we get very little of the prisoners’ lives or thoughts outside of the play. The art and artistry of Shakespeare's play and the mounting of it doesn't just gradually commandeer the film, it swallows it whole at an early stage, with the movie only occasionally referring back to the psychologies of the actual inmates. And, yes, that they live vicariously through their roles, and that from the tedium of prison life the play provides an escape so seductive they spend every waking moment thinking about it, may be precisely the point, but for the audience a little more context would have been welcome.

Such reorienting moments do occur, infrequently. Aside from the device of onscreen titling suddenly informing us of the 'actors'' crimes and sentences when they first gather as an ensemble, there is a rather lovely sequence in which their voices, seemingly reading letters home, are overlaid over shots of the prison exterior at night, and drifting past tiny window after window, we sense the lives, dreams and frustrations the huge, solid building confines. And on a couple of other occasions the actors lapse into ad libbing off the Shakespearean text, prompted by some unexplained rivalry or personal revelation. But these moments are too few, and too staccato in their punctuation of the play's narrative to give us anything more than brief, snatched-away glimpses at the men beneath the men beneath the robes.

Because that's the crux of the matter. We are not watching Cassius. Nor are we watching a prisoner playing Cassius, as we might be were the film a straightforward documentary about a prison theatrical production. In fact, we're watching real prisoners play prisoners playing their roles in "Julius Caesar," so the reality of their situations can feel simply too far removed to have any resonance. This is exacerbated by the style of acting these non-professionals employ – perfect for high theatrics, it is just too big, too forced in the non-Shakespearean moments. Again, that doesn’t necessarily have to be a bad thing: the complex layering is a potential source of immense richness. But we never get a sure enough throughline of directorial intent or guiding principle, and so it becomes difficult to navigate the often conflicting currents of artifice and authenticity that flow through the film.

So how much of the interest in any given scene is borrowed from Shakespeare and how much actually earned through canny directorial choices and compelling film craft? There is no doubt plenty of the latter on display – some of the scenes are laid out exquisitely, like the stabbing scene rehearsed in a tiny prison yard with added Greek chorus in the shape of three watching guards, or the dueling speeches scene (sidebar: is Brutus’ “not that I love Caesar less but that I loved Rome more” vs Anthony’s “Friends, Romans, Countymen” the precursor of the rap-off? All this needs is an MC shouting “boom!” every time a barb lands). But it is telling that these are the film’s most successful moments – they are pure theatre reimagined as pure cinema, but the reality of the actors’ backgrounds is all but absent from these sections. They’re simply very imaginatively staged Shakespearean set pieces. And that’s not to detract from that idea — the Shakespearean reinterpretation/restaging boogie has yielded some compelling results, “Richard III,” and “Coriolanus” spring to mind — it’s just that this film sells itself on the extra layer it adds, then fails to deliver on those terms.

It’s by no means a poor film, and certainly doesn’t want for talkability, as this 1000-odd word review might suggest. But in this clash between art and life, art gets all the best lines, the most coherent characters, the most creative treatment and the most screen time. On this slanted playing ground, is it any wonder art wins hands down? And so we emerge with a film that, for all the interesting questions it poses, really owes the vast majority of its watchability not to the non-professional actors, or the writer-directors, or to the intriguing premise, but to some guy called Shakespeare who’s been dead for 400 years. “Julius Caesar” is a cracking play. “Caesar Must Die” is a good testament to that, but if you’re looking for a whole lot more, we’d have to say the emperor is rather underdressed. [B]